Apr
24
2012
--

Can you get “green energy” when the sun’s not shining?

green-solar-energyIt is sometimes claimed that it’s not possible for humans to depend entirely on renewable energy, because green energy is inherently unreliable and therefore it will always be necessary to have conventional power stations as backup. But this turns out not to be the case. Photovoltaic cells (“solar cells”) generate electricity from sunshine. Naturally, they [more...]

Written by | 2,723 views | Tags: , , , , | 0 Comments
Oct
28
2010
--

Can I Get a Government Grant to Weatherize My House and Lower My Energy Bills?

home weatherization house gov (640x480)One of the most cost-effective steps you can take to green your house, lower your energy bills and shrink your environmental footprint is to weatherize your home. Weatherization isn’t a single step process. It generally involves a number of different approaches: adding insulation (as in the photo), sealing cracks, upgrading windows, reducing drafts from doors [more...]

Written by | 2,142 views | Tags: , , , , | 0 Comments
Mar
24
2010
--

How much does hot water cost?

hot-water-cascadeFew people know how much the water from their cold tap costs, and even fewer realise how much the water from their hot tap costs. The cost of cold water in the UK is around a quarter of a penny per liter, so that's our starting point. How much more does it cost to heat [more...]

Written by | 7,685 views | Tags: , , , | 0 Comments
Feb
27
2010
2

What is Einstein's Theory of Relativity, in simple language?

theory-of-relativityAlbert Einstein's theory is known as the Theory of Relativity because its core principle is that the speed of light in a vacuum is always the same, relative to the observer. This is totally unlike the speed of anything else. If you are driving along the motorway at 100km/hr and the car in the next [more...]

Written by | 10,250 views | Tags: , , , , , | 2 Comments
Sep
09
2009
--

How strong are vitro-ceramic (“glass”) cooktops?

Chipped stovetop (photo by Roger Browne - CC-BY)Vitroceramic cooktops are flat and sleek, but they also look fragile. How robust are they? A vitroceramic stove top is a sheet of glassified ceramic which has been heated in such a way as to remove internal discontinuities where cracks would develop. A cooker made from this glass-ceramic substance is surprisingly strong. The instruction manual [more...]

Written by | 6,983 views | Tags: , , , , , , | 0 Comments
Apr
13
2009
--

What’s the difference between a calorie, a kilocalorie, and a kilojoule?

500 kilocalories, 500 Calories, 500000 calories or 2100 kilojoules (sketch courtesy sketchory.com - CC+)In older diet books the energy content of foods is stated in Calories, and yet when we read product labels we may find kilocalories and kilojoules. The prefix “kilo” means a thousand, so what gives? When Nicolas ClĂ©ment devised the Calorie in 1824, he defined it as the energy required to heat one kilogram of [more...]

Apr
10
2009
--

Is the cellphone popcorn trick real or fake?

Photo by Matt Billings - CC-BYYou may have seen videos such as this one, where a group of people at a party put their phones on the table around some corn kernels. They call the phones, and when the phones start ringing, the popcorn pops. Does this really happen? Wouldn’t the phone be doing the same to our brains when [more...]

Written by | 5,666 views | Tags: , , , , , , | 0 Comments
Feb
06
2009
2

Which forms of energy count as green energy?

Wind power at Altamont Pass (photo by Kevin - CC-BY)Green energy is a somewhat nebulous term, but we’ll take it to refer to energy sources that are carbon neutral, and are replenished naturally within timescales of the order of a human lifetime. That gives us quite a few sources of green energy. Hydro power harnesses the energy of moving water. This can take the [more...]

Jan
14
2009
2

Should I install a domestic wind turbine?

More traditional wind power gathering. Jack and Jill windmills, Sussex (photo by david.nikonvscanon CC-BY)In the UK this is new technology in the domestic environment. According to BWEA, a renewable energy trade association, in 2007 approximately 3500 micro- and small-wind turbines were deployed with the UK. The 2008 figures are expected to be higher. Wind turbines providing “green energy” can now be purchased from DIY stores, but should be [more...]

Written by | 10,211 views | Tags: , , , | 2 Comments
Jan
12
2009
--

How much energy does each Google search use, and how much CO2 does it create?

Energy at dusk (photo by Ryan McD - CC-BY)Because Google is such a large organization, there’s considerable interest in its energy consumption. Google has provided some figures, which they say take into account not just the query itself but also activities such as building the search index. That’s a reasonable way to approach the answer, and also one of the easiest to calculate [more...]

Written by | 6,594 views | Tags: , , , | 0 Comments

Privacy Policy | Acknowledgements